The hourly tropospheric NO2 vertical column density (VCD) values measured by TEMPO were used to study the NO2 diurnal andseasonal variability in 34 urban areas over North America and the Caribbean during the period from August 2023 to October 2024. A recently developed algorithm (Fioletov et al., 2024) isolated three components in tropospheric NO2 data: background NO2, NO2 from urban emissions, and from industrial point sources, and then each of these components was analyzed separately. The method is based on fitting satellite data by a statistical model with empirical plume dispersion functions driven by a meteorological reanalysis. Population density and surface elevation data as well as coordinates of major industrial sources were used in the analysis. The background component demonstrated a clear diurnal cycle with a maximum in the early morning and the minimum in the late afternoon. The urban and industrial components, expressed as total NO2 mass in urban and industrial plumes, did not show any obvious diurnal cycle in most areas. Only the Los Angeles and Mexico City urban components demonstrated a clear cycle with a maximum in the late morning and a minimum in the late afternoon. Differences between workday and weekend NO2 levels were also studied. Urban plume NO2 values on Sundays were typically 30%–60% less than workday plume values throughout the day. The exception was Havana, where the difference between working day and Sunday values was only 15%.
Fioletov, V., McLinden, C. A., Griffin, D., Zhao, X., and Eskes, H.: Global seasonal urban, industrial, and background NO2 estimated from TROPOMI satellite observations, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2024-1991, 2024.
How to cite: Fioletov, V., Griffin, D., McLinden, C., Zhao, X., Nowlan, C., and Gonzalez Abad, G.: Background, urban, and industrial NO2 estimated from TEMPO satellite observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1546, https://doi.org/10.5194/egusphere-egu25-1546, 2025.
Currently deployed (GEMS, TEMPO) and soon-to-be launched (S4-UVN) sensors constitute the first GEO satellite constellation for Air Quality observations in the northern hemisphere. The simultaneous availability of similar observations from platforms at LEO and L1 orbital configurations offers a unique opportunity for the integration of a quasi-global Air Quality observing system. In this presentation, we will discuss specific aerosol events to show the complementary nature of GEO aerosol observations and those of LEO (S5P-TROPOMI and S5-UVNS), and Langrange1-EPIC measurements. Integrated GEO, LEO and L1 observations will be used to demonstrate inter-instrument synergy for sensor calibration transfer, and the understanding of the nature of local events in regional and global contexts.
How to cite: Torres, O., Ahn, C., Jethva, H., and Loyola, D.: Complementarity of GEO, LEO, and Lagrange-1 Point Satellite Aerosol Observations , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6723, https://doi.org/10.5194/egusphere-egu25-6723, 2025.
The Geostationary Interferometric Infrared Sounder (GIIRS) on board China’s FengYun-4 satellite series provides a unique opportunity to monitor the tropospheric composition over Asia using hyperspectral infrared observations from a geostationary orbit. In this study, we retrieve atmospheric carbon monoxide (CO), ammonia (NH3), formic acid (HCOOH) and ozone (O3) for the first two years from July 2022 to June 2024 using the FengYun Geostationary satellite Atmospheric Infrared Retrieval (FY-GeoAIR) algorithm. GIIRS measures these atmospheric compounds both day and night with a temporal resolution of 2 hours and a spatial resolution of 12km at nadir. The spatial patterns, seasonal and diurnal variations of these atmospheric compounds over Asia are analyzed using the FY-4B/GIIRS retrievals. In particular, we focus on a case study of the strong emissions from forest fires over the Indochina Peninsula (ICP) in spring due to the agricultural practice of slash-and-burn. The results show that the spatial and temporal variations of wildfire enhancements of CO, NH3 and HCOOH from Southeast Asia are well captured by the FY-4B/GIIRS. In addition, the FY-4B/GIIRS retrievals are validated with ground-based observations of CO and NH3 and compared with model simulations. Our study demonstrates the potential of GIIRS data to improve our understanding of the spatial and temporal variations of important trace gas pollutants over Asia.
How to cite: Zeng, Z.-C., Sheng, M., Liu, S., Han, S., Wang, W., Lee, L., Qi, C., and Lu, F.: Atmospheric composition from the Geostationary Interferometric Infrared Sounder (GIIRS) on board FengYun satellite: First two years of observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8489, https://doi.org/10.5194/egusphere-egu25-8489, 2025.
Formaldehyde (HCHO), a byproduct of volatile organic compound (VOC) oxidation, is commonly used to constrain VOC emissions in chemical transport model (CTM) simulations through its vertical column density (VCD). While satellite observations provide extensive pollution maps of HCHO VCDs, they often involve significant uncertainties in vertical column retrievals, requiring continuous evaluation against ground-based observations. This study evaluates long-term GEMS HCHO products (version 3) by comparing them with Pandora HCHO VCDs from 2022 to 2024. GEMS HCHO VCDs are 10–40% lower but present good agreement (r=0.6–0.76) with Pandora observations, except for regions (Sapporo, Kobe, and Dhaka), where few samples are available due to the limited GEMS scan schedule. We examine the sensitivity of HCHO VCDs using air mass factors (AMFs) with a priori profiles from a five-CTM ensemble model with a fine spatial resolution (9 km) and updated emissions during the ASIA-AQ campaign, instead of using GEMS a priori profile. The ensemble model demonstrates improved agreement (r=0.83) with DC-8 observations compared to the GEMS a priori profile (r=-0.54), reducing overestimations of surface HCHO concentrations. Using vertical shape factors from ensemble model profiles increases AMFs by 20% in the morning at Suwon, improving agreements with MAX-DOAS observations (NMB= 86% to 33%). Our work highlights the need for continuous updates to a priori profile simulations for precise HCHO retrievals.
How to cite: Lee, G., Park, R., Jeong, J., Lee, S., Kim, H., and Kwon, H.-A.: Sensitivity of GEMS formaldehyde vertical columns to a priori profile for air mass factor during ASIA-AQ, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9038, https://doi.org/10.5194/egusphere-egu25-9038, 2025.
Accurate retrieval of tropospheric NO₂ columns relies on precise knowledge of stratospheric NO₂ columns, which can be derived from chemical transport models (CTMs) or estimated through interpolation from regions with minimal tropospheric NO₂ contributions. However, both approaches have their limitations: stratospheric NO₂ fields from CTMs and satellite retrievals often contain biases, and small-scale spatial variations in stratospheric NO₂ can diminish the accuracy of interpolated estimates. These deficiencies can result in significant errors in stratosphere-troposphere separation (STS). In this presentation, we introduce a novel STS approach that combines retrievals from both UV and visible spectra. By leveraging the differing sensitivities of UV and visible wavelengths to tropospheric NO₂, our method provides a more accurate determination of stratospheric and tropospheric NO₂ columns. We will demonstrate the effectiveness of this technique using observations from TROPOMI, GEMS, and TEMPO, showcasing its potential to enhance the accuracy of STS in satellite-based NO₂ retrievals.
How to cite: Yang, K., Wei, Z., and Flynn, L. E.: Retrievals of Stratospheric and Tropospheric Nitrogen Dioxide (NO2) Columns from Satellite Ultraviolet and Visible Spectral Observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10855, https://doi.org/10.5194/egusphere-egu25-10855, 2025.
In the next few decades a large increase in population is expected to occur on the African continent, leading to a doubling of the current population, which will reach 2.5 billion by 2050. At the same time, Africa is experiencing substantial economic growth. As a result, air pollution and greenhouse gas emissions will increase considerably with significant health impacts to people in Africa. In the decades ahead, Africa’s contribution to climate change and air pollution will become increasingly important. The time has come to determine the evolving role of Africa in global environmental change.
The Committee on Earth Observation Satellites (CEOS) envisions an Atmospheric Composition Virtual Constellation that includes existing polar satellites and now geostationary satellites in the Northern Hemisphere: GEMS over Asia (launch 2022); TEMPO over the USA (launch 2023) and Sentinel 4 over Europe to be launched in the 2024 timeframe. However, there are currently no geostationary satellites envisioned over the Global South, specifically Africa and South-America, where we expect the largest increase in emissions in the decades to come. Current initiatives are a combination of a Geostationary satellite over the Middle-East and Norther Africa (MEASMA) and a Geostationary satellite over Sub-Sahara Africa.
In this paper the scientific need for geostationary satellite measurements over Africa will be described, partly based on several recent research achievements related to Africa using space observations and modeling approaches, as well as first assessments using the GEMS data over Asia, and TEMPO over the USA. Our ambition is to develop an integrated community effort to better characterize air quality and climate-related processes on the African continent.
How to cite: Levelt, P. and the MEASMA-AfricaGEO team: Investigating air pollution and climate change on the African continent: a Global South perspective, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11665, https://doi.org/10.5194/egusphere-egu25-11665, 2025.
Satellite observations of nitrogen dioxide (NO2) have been widely used to estimate nitrogen oxide (NOx) emissions and lifetimes, as well as to analyze their weekday or seasonal variability. The TROPOspheric Monitoring Instrument (TROPOMI), with its high spatial resolution of 3.5 x 5.5 km2, has given new opportunities to disentangle and analyze NOx sources. However, instruments in low-earth orbits usually provide only one measurement per day and location.
The Geostationary Environmental Monitoring Spectrometer (GEMS), launched in February 2020, provides hourly daytime observations of NO2 with a spatial resolution of 3.5 x 8 km2 over a large part of Asia. This opens new opportunities to quantify the diurnal variability of NOx emissions and lifetime from space.
In this study, 4 years of GEMS IUP-UB tropospheric NO2 columns have been analyzed together with ERA5 wind, temperature, and ozone data to estimate NOx emissions and lifetime for several emission sources within the GEMS domain. The estimated emissions are compared to emission inventories and TROPOMI-based emission estimates. The high temporal resolution of GEMS with up to 10 observations per day ensures robust data availability, allowing also for the analysis of short-time variability. Using the dataset of 4 years from 2021 to 2024, hourly estimates are of good quality and are used to quantify the diurnal variability of NOx emissions and lifetime.
How to cite: Lange, K., Richter, A., Burrows, J. P., Hong, H., and Bösch, H.: Diurnal emission fluxes and lifetimes of nitrogen oxide estimated from GEMS observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13335, https://doi.org/10.5194/egusphere-egu25-13335, 2025.
Aerosol size information is important to the understanding of aerosol dynamics, which change rapidly over Asia, with size retrieval from geostationary satellite observations being vital. In this study, a deep neural network model was trained using Advanced Meteorological Imager (AMI) level 1b observations, AMI aerosol products, and observation geometries to retrieve the aerosol optical depth (AOD), Ångström exponent (AE), and spectral derivatives of AE (AE′). The fine-mode fraction (FMF) was calculated with a spectral deconvolution algorithm using retrieved AE and AE′ when AOD > 0.2. The retrieved aerosol products were validated using AERONET (AOD at 550 nm: R = 0.829, RMSE = 0.241, MBE = –0.053; AE: R = 0.723; RMSE = 0.235; MBE = 0.005; FMF: R = 0.814; RMSE = 0.083; MBE = 0.011). Case studies of dust-transport and wildfire events in Asia revealed that the retrieved aerosol size products may be used for analysis of sudden pollution events. Monthly average FMF values in Asia were consistent with previous studies, confirming that the retrieved FMF is useful for seasonal aerosol property analysis. Results of this study indicate the potential for comprehensive analysis of aerosol properties in Asia using continuous aerosol size data from geostationary Earth orbit satellite observations.
How to cite: Kim, M., Kim, J., Lee, S., Lim, H., and Cho, Y.: Aerosol Fine-Mode-Fraction Retrieval from GEO-KOMPSAT-2A/AMI using a Deep Neural Network and Spectral Deconvolution Algorithm, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14037, https://doi.org/10.5194/egusphere-egu25-14037, 2025.
We present the status of the Tropospheric Emissions: Monitoring of Pollution (TEMPO) nitrogen dioxide (NO2) and formaldehyde (HCHO) retrievals one year after their public release. After multiple version updates, the TEMPO Level 2 NO2 and HCHO products have undergone significant enhancements to improve the performance and accuracy of the slant column retrievals, air mass factor calculations and post-processing corrections. Upcoming version 4 will include improved destriping for NO2 and background for HCHO corrections. We illustrate the performance of both retrievals, evaluating their fitting uncertainty and showing comparisons with independent correlative measurements and other satellite products showcasing small noise levels, good accuracy, remarkable correlation and well quantified biases. We continue by illustrating the capacity of TEMPO products focusing on different case studies showing TEMPO’s high temporal and spatial resolution. We finalize discussing aspects of the retrievals subject to improvement, our strategies to enhance their performance and the development of near real time pipelines.
How to cite: Gonzalez Abad, G., Nowlan, C., Chance, K., Liu, X., Carr, J., Chong, H., Davis, J. E., Fitzmaurice, J., Flittner, D. E., Geddes, J., Henderson, B., Hou, W., Houck, J., Judd, L., Kwon, H.-A., Knowland, K. E., Chan Miller, C., O'Sullivan, E., Park, J., and Pierce, B. and the TEMPO team: Tropospheric Emissions: Monitoring of Pollution (TEMPO) nitrogen dioxide and formaldehyde retrievals, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14296, https://doi.org/10.5194/egusphere-egu25-14296, 2025.
The Tropospheric Emissions: Monitoring of Pollution (TEMPO) is part of the global geostationary air quality monitoring constellation. It is the first satellite instrument in geostationary orbit dedicated to monitor air pollutants across North America. Its observational coverage extends from Mexico City to the Canadian oil sands and from the Atlantic Ocean to the Pacific, with hourly measurements at a resolution approaching neighborhood scale. Following its successful launch in April 2023, TEMPO began nominal operations in October 2023. TEMPO L2 data products (NO2, HCHO, Cloud and total ozone) were made publicly available in May 2024, following the release of Level 1 data in February 2024. As of December 2024, these products have been classified as the Provisional maturity level.
This presentation highlights the evaluation of the TEMPO total ozone (O3TOT) product and introduces improvements to the TEMPO ozone profile (O3PROF) product. We present a comparative analysis of total ozone columns (TOCs) from TEMPO observations against data from other satellite instruments, such as OMPS, OMI, and TROPOMI, as well as ground-based measurements from Pandora, Brewer, and Dobson instruments. Additionally, we present enhancements to the TEMPO O3PROF algorithm, particularly the empirical correction, which is scheduled for release this year. Furthermore, we compare TEMPO tropospheric ozone columns with those from EPIC, OMI, and TROPOMI satellites. Lastly, the TEMPO O3PROF product is evaluated using ground-based observations, including data from the Tropospheric Ozone Lidar Network (TOLNet) and ozonesonde observations.
How to cite: Liu, X. and Park, J. and the TEMPO ozone team: Status of the TEMPO total ozone and ozone profile data products: A comprehensive validation using various satellites and ground-based observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14533, https://doi.org/10.5194/egusphere-egu25-14533, 2025.
Accurate estimation of ground-level ozone (O₃) concentration is crucial for assessing its health impacts and devising effective control strategies. Traditional methods relying on polar-orbit satellites offer limited, single-time measurements, failing to capture the significant diurnal variability of O₃. This study utilizes the Geostationary Environment Monitoring Spectrometer (GEMS), a next-generation geostationary satellite, to retrieve hourly O₃ concentrations. The GEMS data not only accurately captures hourly O₃ levels (R² = 0.94) but also significantly enhances the precision of daily maximum 8-hour average (MDA8) O₃ estimates, particularly in semi-urban regions, with an increase in R² by over 0.10 and a reduction in absolute error exceeding 7 μg/m³. Furthermore, our analysis reveals a 30% decrease in O₃-related health risks, with both short-term and long-term mortality rates lower than previous estimates based on polar-orbit satellites. This reduction particularly notable in semi-urban and rural areas, where satellite data is more critical due to the scarcity of ground measurements compared to urban areas. These findings suggest that previous assessments may have overestimated total mortalities and urban-rural spillover effects. Our study highlights the importance of employing high temporal resolution geostationary satellites like GEMS to accurately capture O₃ diurnal variability, providing a robust foundation for health risk assessments and guiding regulatory interventions to address O₃ pollution in China.
How to cite: Song, G., Li, S., Xing, J., Dong, J., and Yang, J.: GEMS Hourly Ozone Data: Enhancing MDA8 Estimates and Reducing Overestimated Health Risks, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15013, https://doi.org/10.5194/egusphere-egu25-15013, 2025.
The Advanced Himawari Imager onboard the Himawari-8/9 geostationary satellite offers a powerful tool for aerosol monitoring at high temporal resolution, with observations available every 10 minutes. Aerosol optical depth (AOD), a key parameter for characterizing aerosols, is commonly retrieved using physics-based algorithms that depend on prior assumptions about surface reflectance and aerosol models. However, these assumptions often fail to account for the complexities of land and atmospheric conditions. This study introduces a novel AOD retrieval algorithm that enhances the accuracy of surface reflectance estimation and aerosol modeling by utilizing time-series geostationary observations and clustering aerosol properties based on precise ground-based measurements. AOD retrievals were performed for the period from 2022 to 2023 over southern China, primarily Guangdong Province, and validated using ground-based measurements from the AErosol RObotic NETwork (AERONET) and the Sun-sky radiometer Observation NETwork (SONET). The results were also compared against aerosol products from the MODerate Resolution Imaging Spectroradiometer (MODIS). The proposed algorithm demonstrated strong agreement with AERONET and SONET observations, achieving a correlation coefficient of 0.74, an RMSE of 0.18, and over 52% of retrievals falling within the expected error (EE) range of ±(0.05 + 15%). By comparison, the AOD products from the Japan Aerospace Exploration Agency (JAXA) had a lower correlation coefficient of 0.232, an RMSE of 0.330, and only about 30% of retrievals within the EE of ±(0.05 + 15%). Furthermore, the proposed algorithm outperformed MODIS in terms of accuracy over their shared retrieval regions. The algorithm’s performance benefits from a newly developed scattering scheme that significantly enhances diurnal retrieval accuracy, making it a promising approach for application to other geostationary satellites.
How to cite: Wong, M., Jin, J., Li, J., Lee, K., Nichol, J. E., and Chan, P.: An advanced aerosol optical depth retrieval algorithm based on an improved scattering angle scheme for Geostationary satellite, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15516, https://doi.org/10.5194/egusphere-egu25-15516, 2025.
The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Instrument is a NASA Earth Venture Instrument (EV-I) project selected on November 8, 2012 in response to the second Stand Alone Mission of Opportunity Notice. The Smithsonian Astrophysical Observatory (SAO) under the direction of the TEMPO Principal Investigator (Pl) at SAO is the lead organization for the project, responsible for TEMPO instrument development data products and science.
The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Instrument [Zoogman et al., 2017] is dispersive spectrometer designed to measure solar back-scatter light in the ultraviolet (UV) and visible (VIS) spectral ranges. The TEMPO instrument draws on several decades of heritage spectrometers (GOME, SCIAMACHY, OMI, TROPOMI, GOME-2, and OMPS; Burrows et al., 1999; Bovensmann et al., 1999; Levelt et al., 2018; Munro et al., 2016; Flynn et al., 2014) operating in low-earth-orbit (LEO), adapting and applying the technology for a geostationary satellite mission designed to monitor air quality over North America. TEMPO takes advantage of a commercial geostationary host spacecraft to make the first North American tropospheric trace gas measurements from GEO. Novel to TEMPO are hourly measurements (or less) during daylight hours at high spatial resolution (2 × 4.75 km2 at the center of field of regard) enabling the quantification of spatial and temporal variations of trace gases and aerosols at scales relevant for understanding urban air quality in the troposphere.
As part of the PI-led TEMPO Science Team, validation of Level 2 NO2, HCHO and O3 column data products recently achieved provisional status in the TEMPO Validation Plan (NASA, 2023). This effort was completed under a best-efforts approach leveraging measurement and modeling assets and many scientist volunteers’ hours to produce a draft validation report currently under review. This talk will provide an overview of the TEMPO validation effort, specifically highlighting the range of contribution from the ad-hoc TEMPO validation team and the resulting validation of the TEMPO gas products.
How to cite: Newchurch, M., Cohen, R., Szykman, J., Pierce, B., Liu, X., Flittner, D., Henderson, B., Judd, L., and Chance, K.: TEMPO Provisional Validation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13818, https://doi.org/10.5194/egusphere-egu25-13818, 2025.
In the troposphere, ozone is a powerful greenhouse gas and air pollutant, harming human health and ecosystems. In the stratosphere, ozone is essential for protecting life on Earth by absorbing harmful ultraviolet (UV) radiation from the Sun. It also plays a key role in maintaining the Earth's radiative balance and stratospheric temperature structure. Monitoring both layers supports tracking pollutant transport, climate regulation, and environmental health.The Geostationary Environmental Monitoring Spectrometer (GEMS) onboard the GEO-KOMPSAT-2B satellite provides high temporal and spatial resolution data on ozone, its precursors (NO₂ and HCHO), SO2, and aerosols over East Asia. The two primary ozone products available from GEMS are total column ozone (O3T) and ozone profile (O3P). The total column ozone is derived using the historical TOMS look-up table algorithm, while the ozone profile product, offers detailed vertical information across 24 atmospheric layers, with an optimal estimation based inversion.
This study describes improvements in the GEMS ozone profile retrieval leading to version 3.0. Compared to 2.X versions, the key updates are as follows: (1) irradiance offset correction are implemented to address the solar diffuser-induced seasonal variation and optical degradation-induced long-term variation, (2) soft calibration is applied to correct residual radiometric biases in the normalized radiances, (3) wavelength shifts are corrected for both radiance and irradiance, and (4) the instrument response function is updated from pre-flight measurements to on-orbit simulations. This has brought the tropospheric O₃ closer to the observations from OMI and TROPOMI. Furthermore, the integrated total column O₃ demonstrates better agreement with ground-based Pandora observation compared to the GEMS O3T product. We also evaluate the information content of ozone profiles in summer during the 2022 ACCLIP campaign and in winter during the 2024 ASIA-AQ campaign. We will discuss how the GEMS ozone profile product adds value in understanding the meteorological modulation of summertime ozone in the troposphere and the dynamical processes affecting wintertime ozone in the upper troposphere and stratosphere.
How to cite: Bak, J., Kim, J., Hong, H., Lee, W.-J., Lee, D., Kim, J., Liu, X., Keppens, A., and Heue, K.-P.: GEMS Ozone profile retrieval: impact of version 3.0 improvements and validations during ACCLIP and ASIA-AQ campaigns. , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16847, https://doi.org/10.5194/egusphere-egu25-16847, 2025.
The PEGASOS project (Product Evaluation of GEMS L2 via Assessment with Sentinel-5P and other Sensors) aims at the evaluation of the operational GEMS L2 data products Ozone (total, tropospheric, profile), NO2, SO2, HCHO as well as cloud-, aerosol- and surface parameters. For the evaluation of the GEMS L2 products, comparisons with space-borne instruments (including TROPOMI/S5P, OMI/Aura, GOME-2/MetOP-ABC, VIIRS/S-NPP, AMI/GK-2A, CALIOP/CALIPSO) and with ground-based measurements/networks (ozone-sondes, Dobson, Brewer, Max-DOAS, NDACC, PGN) are performed.
In a second phase, comparisons for TEMPO with those LEO and ground-based measurements are planned to be included in the PEGASOS project.
In this contribution we provide an overview of the PEGASOS project and summarize the activities performed so far for evaluating the GEMS L2 data products mentioned above. The ESA-funded PEGASOS project is coordinated by the German Aerospace Center (DLR) and the consortium is completed by the Aristotle University of Thessaloniki (AUTH), the Royal Belgian Institute for Space Aeronomy (BIRA-IASB), and the Institute for Environmental Physics of the University of Bremen (IUP-UB).
How to cite: Lutz, R., Loyola, D., Zehner, C., Lee, W.-J., Hong, H., and Kim, J.: The PEGASOS project for comparisons of Geo-Ring data with LEO and ground based data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17580, https://doi.org/10.5194/egusphere-egu25-17580, 2025.
The new satellite technology of the GEO-Ring constellation, offering high-quality, high-temporal-resolution observations of trace gases and aerosols, represents a transformative advance in air quality monitoring. Within the framework of the Horizone Europe CAMEO (CAMS Servive Evolution) project, efforts have focused on integrating GEMS satellite retrievals into ECMWF’s Integrated Forecast System (IFS) to enhance atmospheric composition analyses and forecasts under the Copernicus Atmosphere Monitoring Service (CAMS).
During the first phase of the project, updates to the IFS enabled the assimilation of geostationary GEMS data alongside polar-orbiting satellite observations. Initial evaluations of GEMS version 2 products provided valuable insights into their strengths and limitations, including the identification of biases and their impact on model forecasts.
The operational integration of GEMS NRT NO₂ and O₃ data into the IFS cycle CY49R1 was successfully achieved, with continuous monitoring by CAMS. The release of NRT GEMS retrieval version 3 in December 2024 demonstrated substantial improvements in data quality. Preliminary results indicate significant reductions in biases compared to version 2, particularly for NO₂. The high temporal and spatial resolution of GEMS retrievals captures diurnal patterns, such as rush hour peaks and seasonal variability, being critical for urban air pollution dynamics. For NO₂, comparisons of the NRT GEMS NO2 version 2 data with the IUP-UB alternative retrieval from the University of Bremen revealed improved agreement with TROPOMI and model outputs, reducing biases. For GEMS O₃, assimilation experiments show comparable analysis results to TROPOMI, whereas validations by independent observations show local forecast improvements, particularly over polluted regions.
By combining geostationary and polar-orbiting satellite data, this work highlights the potential for a synergistic approach to address gaps in air quality monitoring. The findings underscore the important role of geostationary platforms in complementing polar-orbiting satellites, capturing dynamic atmospheric processes, and advancing global air quality forecasts. Future efforts to integrate TEMPO and Sentinel-4 data into the CAMS global monitoring system promise cutting-edge improvements in air quality modeling.
How to cite: Paschalidi, Z., Inness, A., Flemming, J., Ribas, R., Lange, K., and Richter, A.: Integrating geostationary satellite data into CAMS: Insights from the CAMEO project and GEMS data assimilation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17636, https://doi.org/10.5194/egusphere-egu25-17636, 2025.
This study presents a case-based evaluation of Geostationary Environment Monitoring Spectrometer (GEMS) ozone products using daily ozonesonde measurements during pre-ACCLIP (2021) and ACCLIP (2022) campaigns. The analysis uses a total of 62 ozonesonde profiles along with atmospheric reanalysis to better understand daily ozone variability and circulation change related to the Asian summer monsoon. The new GEMS ozone profile (version 3) product successfully captures significant variability in tropospheric and lower stratospheric ozone, including major stratospheric ozone intrusion in 2021 and storm-induced tropospheric ozone decreases in 2022. These variations were closely related to convective activities associated with the Asian monsoon rainband and strong anticyclones in the upper troposphere and lower stratosphere. The comparison between ozonesonde data and GEMS ozone products demonstrates GEMS's capability to detect these dynamic ozone variations, highlighting its potential in monitoring chemical transport and regional-scale air quality in Asia.
How to cite: Kim, J., Oh, S., Bak, J., Koo, J.-H., Park, S.-S., and Lee, W.-J.: Event-based GEMS ozone evaluation using consecutive summertime ozonesonde measurements during ACCLIP, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19234, https://doi.org/10.5194/egusphere-egu25-19234, 2025.
GEMS data is constantly improved through ongoing validation and evaluation efforts. The ASIA-AQ field campaign conducted in early 2024 provided an opportunity to expand the GEMS validation area to Southeast Asia. In particular, aerial observations produced accurate vertical profile information of chemical substances, which enabled the evaluation of the uncertainty of GEMS input data. In addition, the Pandora Asia Network Project was completed in late 2024, with a total of 20 Pandoras installed in seven Southeast Asian countries. Real-time validation is now available in most GEMS scan regions, excluding South Asia. Meanwhile, the GEMS retrieval algorithm update was recently completed, and data distribution began in late 2024, and additional updates are planned for later this year. The latest results and future plans for GEMS data validation and improvement are presented in this study.
How to cite: Chang, L., Hong, H., Kim, J., Kim, D., and Lee, D.: Current status of validation and improvement of GEMS data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19934, https://doi.org/10.5194/egusphere-egu25-19934, 2025.
Aerosols in the atmosphere affect radiative forcing directly and indirectly. The single scattering albedo(SSA) of the aerosols describs it absorbs or scatters photons reaching the aerosol layers. Therefore, it is significant to observe SSA with the total burden (i.e., aerosol optical depth) to understand the role of aerosols in the atmosphere. Satellite-based remote sensing data provides global aerosol information. However, the accuracy of a few aerosol parameters (e.g., SSA) is not yet sufficient due to the lack of information in the measurements. Despite its limited spatial coverage, ground-based remote sensing measurements have provided reliable aerosol information as it is less affected by surface reflectance and can measure multiple angles. Previous studies developed combination retrieval techniques that use both ground and satellite measurements to complement the limitations of each method. In this study, we assessed the SSA products from ground and satellite instruments over Asia, where large amounts of aerosol persist throughout the year. We also introduce a combination technique using the EPIC and SMART-s measurements to provide reliable SSA data in the ultraviolet wavelengths.
This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE)
How to cite: park, S.: Spatiotemporal variability of single-scattering albedo over Asia using ground- and satellite-based remote sensing, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7802, https://doi.org/10.5194/egusphere-egu25-7802, 2025.
Based on a number of low-Earth orbit (LEO) and geostationary (GEO) satellite data, the spatiotemporal pattern of aerosol optical depth (AOD) and the vertical column density of nitrogen dioxide (NO2 VCD) was examined in Southeast Asian countries. Especially, we looked into the spatial distribution of AOD and NO2 VCD in each administrative district, which is helpful for the inter-discipline studies about health risk or environmental policy impact in a local scale. For this study, we used the AOD obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Geostationary Environment Monitoring Spectrometer (GEMS) measurements, and NO2 VCD from the Ozone Monitoring Instrument (OMI) measurements. First, climatological mean and diurnal variation of AOD and NO2 VCD were examined in both national and city scale. We found that there is large difference of AOD and NO2 VCD between national and city scale mean pattern in Thailand, Malaysia, and Indonesia, showing the higher developing region in Southeast Asia. Second, we found that contrast of monthly variation between mainland (e.g., Thailand, Lao PDR, etc.) and maritime (e.g., Malaysia, Indonesia, etc.) regions because the seasonal pattern and environmental properties used to be different according to the latitude. We will extend this analysis to other chemical species (SO2 and HCHO) to prepare the typical air quality information in Southeast Asian countries, where the air quality issue is getting more important as the economic development is being accelerated. We will also investigate the effect of the biomass burning to the quantity variation of AOD and columnar density of gaseous pollutants more in detail.
How to cite: Lee, D., Na, S., Yoo, J.-A., and Koo, J.-H.: Spatiotemporal pattern analyses of AOD and NO2 VCD in Southeast Asian countries using low-Earth and geostationary orbit satellite data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15879, https://doi.org/10.5194/egusphere-egu25-15879, 2025.
EUMETSAT will operate the Copernicus Sentinel-4/UVN imaging spectrometer, which is hosted on the Meteosat Third Generation - Sounder (MTG-S) satellite. The first satellite in this series is scheduled to launch in the second half of 2025.
Developed by Airbus Defence and Space under an ESA contract, Sentinel-4/UVN is designed to monitor atmospheric trace gases - such as ozone, nitrogen dioxide, sulfur dioxide, formaldehyde and glyoxal - as well as aerosol and cloud properties from hyperspectral measurements in the UV, Visible and Near-Infrared (UVN). It provides high spatial resolution and hourly coverage over Europe and northern Africa, which is vital for tracking atmospheric composition and serves as a key input to the Copernicus Atmosphere Monitoring Service (CAMS). This innovative instrument will solidify the European contribution to a constellation of geostationary instruments, including the existing GEMS and TEMPO over Asia and North America, respectively. This Geo-Ring will be complemented by the fleet of Low Earth Orbit air quality missions operating in similar spectral ranges, such as GOME-2, OMI, TROPOMI, OMPS and the new Sentinel-5/UVNS mission, providing global daily coverage.
This presentation will provide an overview of the Sentinel-4/UVN instrument and its products, along with the latest updates on the status of the ground segment developments. Some insight into the analysis of the instrument's calibration key data will be part of the presentation.
We will also present the progress of EUMETSAT's data processing and monitoring facility, which is being prepared for commissioning and routine operations. This includes activities for the preparation of the calibration and validation (Cal/Val) of operational atmospheric chemistry products, performed centrally at EUMETSAT as well as with support from the scientific community.
How to cite: Lindstrot, R., Gimeno Garcia, S., Rüthrich, F., Kumar, V., Gu, M., Taberner, M., Caseiro, A., Hayer, C., Hao, N., Köhler, P., Diekmann, C., Dobber, M., Grandell, J., and Bojkov, B.: The Path to Sentinel-4/UVN Operations: Products, Calibration and Validation, Monitoring, and Data Processing Systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17031, https://doi.org/10.5194/egusphere-egu25-17031, 2025.
Aerosol and ocean remote sensing traditionally rely on top-of-atmosphere (TOA) radiance measurements to retrieve optical properties. However, there are ongoing challenges in retrieving chemical and physical parameters due to the limited information contents of the radiances. Polarization measurements, which are sensitive to several aerosol and ocean parameters, provide additional information on these parameters for more detailed characterization. The polarization measurements also give valuable insights into the interaction between aerosols and the atmosphere. Over the years, numerous efforts have been made to measure polarization, including the POLDER generations and the Glory mission. More recently, two passive multi-angular polarimeters, HARP-2 and SPEXone, were launched in February 2024 as part of the PACE mission. This study analyzed the benefit of measuring polarization for retrieving aerosols and oceans based on the optimal-estimation method (OEM). The retrieval sensitivities of two measurement types are compared: one using radiance data alone and another combining radiance with Degree of Linear Polarization (DoLP). We aim to develop an algorithm based on the optimal estimation method that can retrieve aerosols and oceans simultaneously with estimated uncertainties. The key products generated by this algorithm include Aerosol Optical Depth (AOD), the real and imaginary parts of the refractive indices, Fine Mode Fraction (FMF), particle size parameters, and ocean parameters (e.g., ocean surface roughness, chlorophyll-a concentration and CDOM). The improved retrieval capabilities may contribute to a better understanding of atmosphere-ocean interactions.
Acknowledgements
This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE)
How to cite: Lee, S. and Jeong, U.: An Optimal-Estimation-based Algorithm for Simultaneously Retrieving Aerosols and Ocean Parameters using Multi-angular Polarimetric Measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17189, https://doi.org/10.5194/egusphere-egu25-17189, 2025.
Although the total amount of methane (CH₄) is significantly lower than that of carbon dioxide (CO₂), methane is known to accelerate global warming due to its high Global Warming Potential (GWP) and recent increasing trends. As countries around the world prepare for the era of carbon neutrality, they are competitively developing systems to take a leading role in calculating emissions. While ground-based observation equipment currently provides relatively accurate data, there are limitations in quantifying greenhouse gases from various sources. These limitations are particularly evident in marine areas and regions with insufficient ground-based observation data. To overcome these challenges, this study aims to develop a CubeSat for greenhouse gas monitoring. We plan to launch the first CubeSat in 2027, followed by the launch of four additional satellites in 2028. However, CubeSats may have lower observational accuracy compared to medium and large-scale satellites, making it crucial to develop algorithms that meet data quality and user requirements. Therefore, this study focuses on developing an algorithm that optimally retrieves methane concentrations. Once developed, this greenhouse gas monitoring algorithm will serve as a foundation for more accurate assessments of emission management policies, climate change prediction resources, and both short- and long-term trends in carbon dioxide and methane emissions.
Acknowledgement
This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE).
How to cite: Choi, H. and Jeong, U.: Prototype Development of Algorithms for CH4 and CO2 Observation Using Cube Satellites, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17477, https://doi.org/10.5194/egusphere-egu25-17477, 2025.
Since the 21st century, the importance of fine-mode particles associated with NO2 has become increasingly prominent on a global scale, driven by reductions in SO2 emissions. NO2, sharing emission sources with aerosols, acts as a precursor for secondary aerosol formation through atmospheric chemical reactions. Ground-based remote sensing measurements provide high temporal resolution of total burden air pollutants. This study analyzed the relationship between aerosol optical depth (AOD) and total column nitrogen dioxide (NO2) from the Pandora instruments operated by the Pandonia Global Network (PGN) and Pandora Asia Network (PAN) to assess the contribution of the nitrate emissions to the aerosols. The daily coefficient of determination (DDC) between NO2 vertical column density (VCD) and AOD was analyzed across various Asian cities. By incorporating water vapor (H2O) VCD as a meteorological adjustment, a significant relationship between NO2 VCD and adjusted DDC was observed, suggesting that in sites with high NO₂ loading, NO2 is highly correlated with the AOD. Pandora’s simultaneous direct sunlight measurements of AOD, H2O VCD, and NO2 VCD provide valuable information on the relationship between atmospheric aerosols and trace gases, contributing to global air quality research.
Acknowledgements
This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment (MOE).
How to cite: Kim, S. and Jeong, U.: Estimations of the contribution of nitrate emissions to the total burden of aerosols in major cities of Asia from the Pandora Asia Network, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17478, https://doi.org/10.5194/egusphere-egu25-17478, 2025.
EUMETSAT will operate the Copernicus Sentinel-5/Ultraviolet, Visible Near-infrared Short -wave infrared (UVNS) imaging spectrometer, which is hosted on the EUMETSAT Polar System - Second Generation (EPS-SG) A satellites. The first satellite in this series is scheduled to launch in the second half of 2025.
Developed by Airbus Defence and Space under an ESA contract, Sentinel-5/UVNS is designed to monitor atmospheric trace gases - such as ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, glyoxal, methane, and carbon monoxide - as well as aerosol and cloud properties. With its high spatial resolution and near-daily global coverage, it provides essential data for tracking atmospheric composition and supports the Copernicus Atmosphere Monitoring Service (CAMS). Sentinel-5/UVNS will complement and extend the existing fleet of Low Earth Orbit air quality missions operating in the UV, visible, as well as near infrared spectral ranges, such as GOME-2, OMI, TROPOMI and OMPS. Furthermore, it will play a pivotal role in the constellation of geostationary air quality missions consisting of Sentinel-4, GEMS and TEMPO, forming the Geo-Ring, by serving as a travelling standard to monitor and maintain the consistency of the geostationary mission data.
This presentation will provide an overview of the Sentinel-5 instrument and its products, along with the latest updates on the status of the ground segment developments as well as the preparation of offline processing systems for the analysis of in-orbit calibration measurements.
We will also discuss the progress of EUMETSAT's data processing and monitoring facility, which is being prepared for commissioning and routine operations. This includes activities for the preparation of the calibration and validation (Cal/Val) of operational atmospheric chemistry products, performed centrally at EUMETSAT as well as with support from the scientific community.
How to cite: Hao, N., Lindstrot, R., Köhler, P., Diekmann, C., Wang, Y., Gu, M., Poli, G., Kumar, V., Hayer, C., Rüthrich, F., Gimeno Garcia, S., Lee, C. G.-Y., Munro, R., and Bojkov, B.: The Path to Sentinel-5/UVNS Operations: Products, Calibration and Validation, Monitoring, and Data Processing Systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17674, https://doi.org/10.5194/egusphere-egu25-17674, 2025.
The Pandora spectrometer is a valuable tool for air quality monitoring and satellite validation. From 2020 to 2024, the National Institute of Environmental Research (NIER), in collaboration with the Korea International Cooperation Agency (KOICA), the Korea Environment Corporation (KECO), and the United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP), successfully established the Pandora Asia Network (PAN) by installing 20 Pandora instruments within the field of view of the Geostationary Monitoring Spectrometer (GEMS). These units were installed four in Thailand, three in Indonesia, three in Mongolia, two in Laos, four in the Philippines, three in Vietnam, and one in Cambodia. PAN could provide long-term data to validate GEMS data for Southeast Asia, along with the Pandora instruments installed in Korea, Japan, Singapore, and Malaysia. The comparison results showed a high correlation between GEMS and Pandora. NIER plans to process PAN data in near-real time and provide comparison figures with GEMS, offering greater convenience to GEMS data users. This is expected to contribute not only to GEMS validation but also to monitoring air pollution in the Asian region.
How to cite: Kim, D., Chang, L., Hong, H., Lee, D., Lee, H., Jeong, U., and Kim, S.: Establishment of the Pandora Asia Network and validation of GEMS, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19951, https://doi.org/10.5194/egusphere-egu25-19951, 2025.
Posters virtual: Wed, 30 Apr, 14:00–15:45 | vPoster spot 5
EGU25-7314 | Posters virtual | VPS3
Leveraging TEMPO Data: Tools and Services for Air Quality Monitoring and Research from the Atmospheric Science Data CenterWed, 30 Apr, 14:00–15:45 (CEST) | vP5.17
NASA’s Atmospheric Science Data Center (ASDC) at Langley Research Center will present an overview of the Tropospheric Emissions: Monitoring of Pollution (TEMPO) mission, focusing on the cutting-edge tools and services available to users for air quality research and environmental monitoring. TEMPO is a pioneering geostationary satellite that provides day light hourly observations of pollutants over North America, including measurements of ozone, nitrogen dioxide, and other critical pollutants.This presentation will highlight the ASDC’s role in archiving, distributing, and providing user support for TEMPO data. Attendees will be introduced to data access tools, visualization platforms, and analysis services designed to facilitate the use of TEMPO observations for scientific research and decision-making. Key resources, such as NASA Earthdata Search, Earth GIS, OPeNDAP, Worldview, Github Tutorials and Harmony services on the cloud, will be showcased, demonstrating how researchers can efficiently explore and download high-resolution data products.Additionally, the presentation will cover the application of TEMPO data in studying air quality trends, emission sources, and the impacts of pollution on public health and climate. Attendees will also gain insights into ASDC's open science initiatives, which encourage collaboration and data sharing to enhance the impact of TEMPO and NASA’s broader Earth science mission.Through this presentation, the ASDC aims to empower the scientific community with the tools and knowledge needed to harness the full potential of TEMPO data in addressing pressing environmental challenges.
How to cite: Mahmoud, H. and Radkevich, A.: Leveraging TEMPO Data: Tools and Services for Air Quality Monitoring and Research from the Atmospheric Science Data Center, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7314, https://doi.org/10.5194/egusphere-egu25-7314, 2025.
EGU25-15191 | Posters virtual | VPS3
Nitrous Acid (HONO) Retrievals from wildfire events by using Geostationary Environment Monitoring Spectrometer (GEMS) ultraviolet spectraWed, 30 Apr, 14:00–15:45 (CEST) | vP5.18
Nitrous acid (HONO) is known to be the significant source of hydroxyl radicals (OH), impacting air quality and climate as a major oxidant in the atmosphere. Many studies have highlighted that the photolysis of HONO can produce substantial amounts of OH throughout the day. Despite the crucial role of HONO in tropospheric chemistry, more research is needed to improve understanding of global HONO budgets. To address this, we developed a prototype HONO retrieval algorithm from the Geostationary Environment Monitoring Spectrometer (GEMS). The retrieval algorithm comprises two major processes, commencing with the spectral fitting of UV spectral range (343-371 nm) using the direct fitting method to obtain the slant columns. Subsequently, the conversion of slant columns into vertical columns is achieved by applying the air mass factor. The last step involves background correction, wherein the slant column amounts of HONO included in the radiance reference spectrum are added to the differential slant columns. Enhancements of HONO resulting from wildfire events in Asia were detected using GEMS. Refining the GEMS HONO retrieval algorithm is expected to enhance our understanding of the diurnal cycle of HONO, along with tropospheric chemistry in Asia.
How to cite: Cha, H., Kim, J., Chong, H., González Abad, G., Park, S. S., and Lee, W.: Nitrous Acid (HONO) Retrievals from wildfire events by using Geostationary Environment Monitoring Spectrometer (GEMS) ultraviolet spectra, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15191, https://doi.org/10.5194/egusphere-egu25-15191, 2025.
EGU25-14596 | Posters virtual | VPS3
The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Level 0-1 Processor – Radiometric calibration and intercomparisonWed, 30 Apr, 14:00–15:45 (CEST) | vP5.19
We present the status of the Level 0-1 processor for the Tropospheric Emissions: Monitoring of Pollution (TEMPO), with a primary focus on radiometric calibration. Multiple version updates have significantly improved the TEMPO Level 1 products, enhancing the quality of Level 2 products and enabling the detection of city lights, nightglow, and aurora signals during twilight hours. However, assessments of TEMPO Level 1 data (versions 1 to 3) indicated overestimations of Sun-normalized radiances when compared to radiative transfer calculations. To investigate these biases, we compared TEMPO solar irradiance measurements to those from multiple independent instruments and a high-resolution reference solar spectrum. For Earth radiance assessments, we conducted intercomparisons with spaceborne measurements from the Advanced Baseline Imager (ABI) instruments onboard the Geostationary Operational Environmental Satellite (GOES)-16 and -19. Located at the checkout position of 89.5°W for post-launch testing, GOES-19 ABI has provided comparable viewing geometries with TEMPO (at 91.0°W) over North America. On the other hand, comparisons with GOES-16 ABI (located at 75.2°W) may require corrections for viewing angles and bidirectional reflectance distribution function (BRDF) effects due to larger differences in geometries. Additionally, we compared TEMPO Sun-normalized radiances with radiative transfer simulations over Railroad Valley, which use ground-based surface reflectance measurements as input. In this work, we present the intercomparison results and propose potential approaches to mitigate the radiometric biases.
How to cite: Chong, H., Liu, X., Houck, J., Flittner, D. E., Carr, J., and Hou, W. and the TEMPO instrument calibration team: The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Level 0-1 Processor – Radiometric calibration and intercomparison, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14596, https://doi.org/10.5194/egusphere-egu25-14596, 2025.
EGU25-19628 | Posters virtual | VPS3
Estimation and validation of direct aerosol radiative forcing in the Korean peninsula using the GEMS datasetWed, 30 Apr, 14:00–15:45 (CEST) | vP5.20
In this study, we conducted the estimation of shortwave aerosol radiative forcing using the aerosol optical depth (AOD) and supplementary information from the Geostationary Environment Monitoring Spectrometer (GEMS) dataset. We used the libRadtran package for the radiative transfer modeling (RTM), and used the radiative forcing values provided from the Aerosol Robotic Network (AERONET) system for the input value of RTM and the validation task. Total 6 sites in the Korean peninsula are target regions, such as Seoul (Yonsei University and Seoul National university), Anmyeon, Gwangju, Gangneung, and Ulsan. In detail, we used the climatological mean of surface albedo and asymmetry parameter at 4 shortwave channels (440, 675, 870, and 1020 nm), and used daily representative single scattering albedo provided from the GEMS dataset in order to consider the different aerosol type (dust, non-absorbing, and black carbon types). These set-up conditions were finally decided after a number of sensitivity tests. As a result, our estimation of direct aerosol radiative forcing (DARF) at the surface and top of the atmosphere (TOA) shows high correlations with the DARF from the AERONET (correlation coefficient is 0.65 to 0.85 in all 6 sites). Our estimated DARF is a little underestimated compared to the DARF of AERONET, and it seems natural due to the spatial resolution difference. With this high performance, we can provide the daytime hourly variation of DARF over the whole Korean peninsula, which can be useful information to a number of application in the future.
How to cite: Koo, J.-H., Lee, J., and Yoo, J.-A.: Estimation and validation of direct aerosol radiative forcing in the Korean peninsula using the GEMS dataset, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19628, https://doi.org/10.5194/egusphere-egu25-19628, 2025.
